"The primary objective of this campaign is to encourage viewers to download and play Neverwinter and Star Trek Online. Remember, this campaign is CPC based so the more creators that sign up using your link, the bigger the payoff for you!"

- Excerpt of a marketing campaign proposal for "influencers" obtained by Kotaku.

It's 2016, and developers have come to appreciate and rely upon YouTubers and "influencers" who can drum up interest in their game by simply broadcasting themselves playing it on platforms like YouTube or Twitch.

While some developers simply send out Steam keys and hope for the best, others (typically big publishers) contract with marketing firms to ensure that scores of "influencers" will be getting the word out about their games.

Understanding how game companies market their games helps shed some light on how the YouTuber business works, but that understanding is often hard to come by -- unless a marketing firm sends you a marketing plan by mistake.

That seems to be what happened to Kotaku, which published a report today detailing a promotional campaign invitation it mistakenly received from marketing firm Reelio on behalf of MMORPG maven Perfect World Entertainment.

The invitation was seemingly intended for high-profile YouTubers, and when Kotaku requested more information Reelio sent over a list of guidelines that are worth looking over, if only to get a better sense of how video game YouTubers who are interested in creating sponsored videos are being asked to talk about games.

"Do: Find something in the game to gently poke fun at," reads one excerpt published by Kotaku. "Don't: Curse or use foul language in your video."